Are you sure the passphrase wasn't the password of his encrypted wallet file instead? What your script is doing, it's to use the passphrases as private keys of adresses hashed with SHA256. So it's a brainwallet basically. But if it was so "simple" I guess your friend would have already tried it with one tool or another during those 10 passed years, especially with the exponential increasing price of BTC, don't you think? Anyway I hope you will be able to find more clues. May Santa Claus be generous with you.
I do not know how in 2014 mining worked in the sense, wallet and mining to the btc address happened at the same time?
It was transparent to the miner? Not sure.
From what he told, he used a password or passphrase which then lead to a BTC address and than mined to that address.
He does not have a wallet file.
It's for a friend who think he has the passphrase and wants to see if the addresses have Bitcoin!
If your friend mined bitcoin in 2014, but now has a wallet passphrase, he can unlock the wallet file and access his bitcoin.
If not, he need an unenrypted wallet file to access his bitcoin.
You can not brute force Bitcoin private key from Bitcoin public addresses that has balance, because if you can do it, many other people would have done it before you.
Private key > Public Key > Public address, it's always one-way process, not way to do backwards like Public address > Pubic Key > Private key.
Ad I mentioned he does not have a wallet file.
He thinks he knows the passphrase or password used to create the address at command line for mining. He knows that he mined some coins.
I do not know what process was back than. I am guessing, enter a password and than everything else was not so explicit and than started to mine.
I am not trying to brute force anything. As I explain we have a "known" passphrase password and want to use the script to create the pkey which leads to an address to see if it exists and contains coins.
The script above takes some passphrase or passowrd, creates pkey, than creates a valid address and than it checks if the address has bitcoin.